The present invention relates to a sealing arrangement.
More particularly, the present invention is concerned with a sealing arrangement for a two-member couple, such as a cylinder-piston unit.
It is known in the art to provide a sealing arrangement having a sealing ring interposed between two members of a couple. The sealing ring has a face which engages one of the members (e.g. the piston) of the couple. Such a sealing ring has a rectangular cross-section and extends over an entire width of a groove provided on the other member (e.g. the cylinder) of the couple. The sealing arrangement further includes an O-ring which is interposed between the other member of the couple and the sealing ring so as to press the face of the sealing ring against the above-mentioned one member (i.e. the piston).
The face of the sealing ring has two axially spaced edges. The pressing force of the O-ring is concentrated on the area of an intermediate portion of the face of the sealing ring, that is the portion located between the axially spaced edges of the face. However, the edges are only slightly (if at all) under the influence of the pressing force. In other words, the further from the intermediate portion towards the edges of the face, the smaller the influence of the pressing force exerted by the O-ring on the sealing ring.
Thus, during the operation of such a sealing arrangement the edge portions may deflect in a direction away from the above-mentioned one member of the couple. Obviously, even a small deflection of edges of the sealing ring away from the above-mentioned one member will lead to a leak between the members of the couple.